Differences Between Galvalume and Galvanized Steel Roof

If you are planning to replace your steel roof or you are building a new home, you can consider having a metal roof. Then it becomes important to understand the differences between galvalume and galvanized steel roof. This will ensure that you receive the best performance and use from your metal roof. 

In many steel roof applications for residential homes, including beach houses situated close to the beach or coastal areas, Galvalume corrugated sheet is a more corrosion-resistant and better option when compared to galvanized steel sheet. 

However, Galvalume steel is better for standing-seam metal roofs and prefabricated metal-wall panel applications that feature concealed fasteners. Galvalume panels are not recommended for steel-roofing systems that feature exposed fasteners such as ribbed or corrugated steel roofs. 

Galvalume steel roof options are available in pre-painted (pre-coated) or bare versions. Galvalume offers an exceptional lifespan when it comes to both exposed and pre-painted panels. Galvalume and galvanized steel both weigh between 100 to 150 pounds per 100 square feet and usually contain around 35% recycled post-consumer steel content. 

What Is Galvalume?

A company by the name of Bethlehem Steel produced this product where it was introduced onto the market in 1972. This means that this product has been in use for close to six decades. Galvalume, shares similarities with galvanized steel since they are both produced through the hot-dip process or method. However, instead of 100% aluminum, the process involves a metal-alloy dip that contains around 1.5% silicon, 43.5% zinc, and 55% aluminum. 

- The zinc bonds directly to the steel surfaces which creates a protective layer to corrosion-causing moisture.

- The silicon present in this process improves how the coating adheres to the metal, making sure it remains in place once the steel sheets are bent, stamped, or rolled. 

- Aluminum is a type of metal that reflects heat and is naturally corrosion-resistant. 

How Does Corrosion Occur In Galvalume And Galvanized Steel

Corrosion means the end of any type of metal roofing. Galvanized and galvalume steel roofs are differently affected by corrosion. 

Galvalume Steel

Aluminum is already highly resistant to corrosion so these products tend to corrode a lot slower when compared to galvanized steel. 

Galvanized Steel

Galvanized steel panels will produce a strong chemical bond that is resistant to nicks, scratches, and corrosion. Galvanized steel will also "self-heal" when it comes to small scratches that occur along the cut-edges. As time goes by, the galvanized layer in the steel panels will start to wear down and this is when corrosion will start to spread. 

As the corrosion spreads the steel under the bonded, galvanized layer will start to shed. The corrosion may be slow, but at the same time steady. 

Galvalume and galvanized steel products both provide excellent value across their lifespan. Unlike many other roofing materials like asphalt, for example, ongoing maintenance is not necessary to enjoy long-term longevity, durability, and appearance. 

The roofing installation itself will also play an important role when it comes to how long your metal roof will last. For this reason, it is important to compare quotes and interview at least 3 to 4 roofing contractors to find out more about the costs and options for galvalume or galvanized steel roofs. Here is a link for your reference: https://wzppgi.com/galvalume-roofing-sheet/.